failed to run /usr/bin/make [make bzImage -j 32 CC=/syzkaller/gcc/bin/gcc]: exit status 2
scripts/kconfig/conf  --silentoldconfig Kconfig
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  CHK     scripts/mod/devicetable-offsets.h
  CHK     include/generated/bounds.h
  CHK     include/generated/timeconst.h
  CHK     include/generated/asm-offsets.h
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CC      mm/zswap.o
  CC      mm/sparse.o
  CC      mm/sparse-vmemmap.o
  CC      mm/mmu_notifier.o
  CC      mm/ksm.o
  CC      mm/page_poison.o
  CC      mm/slab.o
  CC      mm/failslab.o
  CC      mm/migrate.o
  CC      mm/kasan/kasan.o
  CC      mm/kasan/report.o
  CC      mm/kasan/quarantine.o
  CC      mm/kasan/kasan_init.o
  CC      mm/huge_memory.o
  CC      mm/khugepaged.o
  CC      mm/page_counter.o
  CC      mm/memcontrol.o
mm/zswap.c: In function ‘zswap_frontswap_store’:
mm/zswap.c:1066:2: error: ‘hlen’ undeclared (first use in this function); did you mean ‘len’?
  hlen = zpool_shrinkable(entry->pool->zpool) ? sizeof(zhdr) : 0;
  ^~~~
  len
mm/zswap.c:1066:2: note: each undeclared identifier is reported only once for each function it appears in
mm/zswap.c:1004:33: warning: unused variable ‘len’ [-Wunused-variable]
  unsigned int dlen = PAGE_SIZE, len;
                                 ^~~
scripts/Makefile.build:310: recipe for target 'mm/zswap.o' failed
make[1]: *** [mm/zswap.o] Error 1
make[1]: *** Waiting for unfinished jobs....
  AR      mm/kasan/built-in.o
mm/khugepaged.c: In function ‘collapse_shmem’:
mm/khugepaged.c:1560:1: warning: the frame size of 2904 bytes is larger than 2048 bytes [-Wframe-larger-than=]
 }
 ^
mm/ksm.c: In function ‘ksm_do_scan’:
mm/ksm.c:2320:1: warning: the frame size of 4880 bytes is larger than 2048 bytes [-Wframe-larger-than=]
 }
 ^
mm/huge_memory.c: In function ‘do_huge_pmd_wp_page’:
mm/huge_memory.c:1381:1: warning: the frame size of 2368 bytes is larger than 2048 bytes [-Wframe-larger-than=]
 }
 ^
Makefile:1048: recipe for target 'mm' failed
make: *** [mm] Error 2